Heading into a critical period in the debate over health-care reform, public approval of President Obama’s stewardship on the issue has dropped below the 50 percent threshold for the first time, according to a new Washington Post-ABC News poll.

Obama’s approval ratings on other front-burner issues, such as the economy and the federal budget deficit, have also slipped over the summer, as rising concern about spending and continuing worries about the economy combine to challenge his administration. Barely more than half approve of the way he is handling unemployment, which now tops 10 percent in 15 states and the District.

The president’s overall approval rating remains higher than his marks on particular domestic issues, with 59 percent giving him positive reviews and 37 percent disapproving. But this is the first time in his presidency that Obama has fallen under 60 percent in Post-ABC polling, and the rating is six percentage points lower than it was a month ago.

Obama has taken on a series of major problems during his young presidency, but he faces a particularly difficult fight over his effort to encourage Congress to pass an overhaul of the nation’s health-care system.